THE booming nations of south-east Asia, whose economies are the fastest-growing in the world, are making the most ambitious attempt yet to control the flow of information on the Internet.

Information ministers of the seven countries in the Association of South- East Asian Nations (Asean) announced last week that they would set up a regulatory body to come up with "appropriate responses" to the Net. They expressed concern about pornography and "disinformation" on the Net which could create racial tension and disharmony. "The influx of objectionable materials via the new electronic media, if left unchecked, will undermine our values and traditions," George Yeo, Singapore's Information Minister, said on Thursday.

Two days earlier, his government had announced that it would license all companies which provide a link to the Internet. This, like a similar move announced by the Chinese government earlier this year, appears to put in place the apparatus for fairly effective censorship: a licensed provider can always have its licence withdrawn, and might be made responsible for the material it makes accessible.

Singapore has successfully controlled access to more conventional sources of information, restricting the circulation of publications which have displeased the authorities, such as the Economist and the Far East Economic Review. Satellite dishes are banned altogether. China's size prevents it from exercising the same control, but it has cracked down on the spread of satellite television. Under threat of losing the lucrative Chinese advertising market, Rupert Murdoch's Star-TV stopped transmitting BBC World Service Television to north-east Asia.

Singapore's decision to tighten Internet rules was not aimed at putting a cordon around information but to "channel and guide" the system, the Deputy Prime Minister, Lee Hsien Loong, said yesterday. There were dangers of completely uncontrolled discussions on sensitive subjects such as race, language and religion.

"It can be done through television, radio and the newspapers," he said. "With the Internet, it's a new medium and you are not quite sure how it will evolve. But potentially it can have a big impact on a large number of people, and very fast." Singapore was developing the Internet to meet its own Asian taste in "entertainment, information and communication".

Yet it is a truism of debate about the Internet that censorship is possible only at the source of information and not at its destination. "The Net interprets censorship as damage and routes around it," said one pioneer.

Under pressure from prosecuting authorities earlier this year, two of the largest Internet providers in Germany tried to cut off access to various pornographic and neo-Nazi discussion areas of the Net. But this had no effect on university networks, and was easily circumvented by technically- minded users. Attempts to censor the neo-Nazi material in particular had the opposite effect - American enthusiasts for free speech reacted violently and rapidly spread copies of the offending material to many of the most distinguished US universities.

The availability of pornography on the Internet is the point at which proponents of Internet censorship push hardest, since it prevents societies applying their own local controls to what is acceptable or not. Baroness Thatcher said in Utah last week: "The dangers to children are enormous. We've got to block certain information ... or make it a crime, with heavy sentencing, to put certain things to the Internet."

As the German episode showed, however, even the most democratic countries differ on what constitutes acceptable political speech, let alone more authoritarian nations such as Singapore. And since everything is discussed on the Internet, from bass fishing to the philosophy of Sir Karl Popper, the number of subjects someone might want to censor is limitless.

The Internet has immense potential for disrupting authoritarian societies and is becoming fashionable in south-east Asia. Cyber-cafes are springing up all over the region, even in Sri Lanka, and the World Wide Web, the portion of Internet which is easy to navigate and use, is growing explosively.

Even if the censor can identify certain sites or discussion groups as containing prohibited material, there can be considerable problems in determining when someone is accessing them. The nature of the Internet means that it is easy to access a computer in Sweden from London via Ohio, San Francisco and Amsterdam. At each hop, the local laws are different, and without the co-operation of all the telecommunications companies carrying all of the traffic, it would be impossible to follow the progress of the call.

This implies that censorship on the Internet will always be the loosest available, since no country can impose its tighter laws on any other. Yet nations which turn their back on the Net will also probably exclude themselves from the front-rank economies of the 21st century, which will increasingly depend on the swift and unimpeded flow of information. It is a tricky bind for the Asean countries, whose brand of paternalistic capitalism has so far proved so successful.